Heretofore, gear grinding machines have been provided to efficiently finish the faces of the teeth of a workpiece, which is a heat-treated gear to be machined, by grinding the workpiece with a grinding wheel, which is a grinding tool. In such a gear grinding machine, repeated grinding causes a decrease in sharpness of the grinding wheel due to the wear thereof. Accordingly, after a predetermined number of workpieces have been ground, the worn grinding wheel needs to be dressed to restore the sharpness of the faces of the threads thereof.
For this reason, conventional gear grinding machines have the dressing function of dressing a worn grinding wheel with a dresser. Such a gear grinding machine having the dressing function is disclosed in, for example, Patent Literature 1.